BUFFALO, N.Y. -- A study by the University at Buffalo shows for
the first time that obese males ages 14 to 20 have up to 50 percent
less total testosterone than do normal males of the same age,
significantly increasing their potential to be impotent and
infertile as adults.

The paper was published online as an accepted article in
Clinical Endocrinology.

The authors are the same researchers in the University at
Buffalo's School of Medicine and Biomedical Sciences who first
reported in 2004 the presence of low testosterone levels, known as
hypogonadism, in obese, type 2 diabetic adult males and confirmed
it in 2010 in more than 2,000 obese men, both diabetic and
nondiabetic.

"We were surprised to observe a 50 percent reduction in
testosterone in this pediatric study because these obese males were
young and were not diabetic," says Paresh Dandona, MD, PhD, SUNY
Distinguished Professor in the Department of Medicine, chief of the
Division of Endocrinology, Diabetes and Metabolism in the UB
medical school and first author on the study. "The implications of
our findings are, frankly, horrendous because these boys are
potentially impotent and infertile," says Dandona. "The message is
a grim one with massive epidemiological implications."

The small study included 25 obese and 25 lean males and was
controlled for age and level of sexual maturity. Concentrations of
total and free testosterone and estradiol, an estrogen hormone,
were measured in morning fasting blood samples. The results need to
be confirmed with a larger number of subjects, Dandona says.

"These findings demonstrate that the effect of obesity is
powerful, even in the young, and that lifestyle and nutritional
intake starting in childhood have major repercussions throughout
all stages of life," he says.

In addition to the reproductive consequences, the absence or low
levels of testosterone that were found also will increase the
tendency toward abdominal fat and reduced muscle, Dandona says,
leading to insulin resistance, which contributes to diabetes.

"The good news is that we know that testosterone levels do
return to normal in obese adult males who undergo gastric bypass
surgery," says Dandona. "It's possible that levels also will return
to normal through weight loss as a result of lifestyle change,
although this needs to be confirmed by larger studies."

The UB researchers now intend to study whether or not weight
loss accomplished either through lifestyle changes or through
pharmacological intervention will restore testosterone levels in
obese teen males.

Co-authors with Dandona are Muniza Mogri, MD, a medical resident
in the UB Department of Pediatrics, Sandeep Dhindsa, MD, clinical
assistant professor of medicine at UB; Husam Ghanim, PhD, research
assistant professor of medicine; and Teresa Quattrin, MD, A. Conger
Goodyear Professor and chair of the Department of Pediatrics,
housed in Women and Children's Hospital of Buffalo.